{
  "$options": {
    "flat_output":true,
    "separator":"."},
  "type": "FeatureCollection",
  "features": [
    {
      "$source": "gsml:GeologicUnit"
    },
    {
      "properties": {
        "@id": "${@id}",
        "description": "$filter{xpath('gml:description')='Olivine basalt'},${gml:description}",
        "gsml:geologicUnitType": "urn:ogc:def:nil:OGC::unknown",
        "gsml:composition": [
          {
            "$source": "gsml:composition"
          },
          {
            "gsml:compositionPart": [
              {
                "$source": "gsml:CompositionPart"
              },
              {
                "gsml:role_value": "${gsml:role}",
                "gsml:role_codeSpace": "urn:cgi:classifierScheme:Example:CompositionPartRole",
                "proportion_dataType": "CGI_ValueProperty",
                "proportion_CGI_TermValue_dataType": "CGI_TermValue",
                "proportion_CGI_TermValue_value": "${gsml:proportion/gsml:CGI_TermValue}",
                "lithology": [
                  {
                    "$source": "gsml:lithology"
                  },
                  {
                    "@id": "${gsml:ControlledConcept/@id}",
                    "name": {
                      "value": "${gsml:ControlledConcept/gsml:name}",
                      "@lang": "en"
                    },
                    "vocabulary": {
                      "@href": "urn:ogc:def:nil:OGC::missing"
                    }
                  }
                ]
              }
            ]
          }
        ]
      }
    }
  ]
}
